A comparative study of the localization of vasoactive intestinal peptide- and substance P-like immunoreactivities in the submandibular salivary glands of mice.

The localization of vasoactive intestinal peptide (VIP)- and substance P (SP)-like immunoreactivities within the submandibular salivary glands (SMG) of Balb/c male mice at 4 to 5 weeks of age were investigated. Two immunocytochemical methods using polyclonal, monospecific antibodies, the indirect immunofluorescence and peroxidase-antiperoxidase (PAP), were used to elucidate the localization of VIP- and SP-like immunoreactivities in the SMG. Both VIP- and SP-like immunoreactivities were positive in the SMG of Balb/c male mice at 4 to 5 weeks of age. The VIP-like immunoreactivity was found in the dense plexuses around the salivary duct and in the small scattered nerves surrounding glandular acini, and particularly in the nerve cell bodies of the submaxillary ganglion. The SP-like immunoreactivity was conspicuously abundant in the excretory ducts with a rich supply of SP-positive nerves, but also very scanty in the acinus areas close to the striated ducts and interlobular excretory ducts. It could be conclusively observed that the localization of the VIP- and SP-like immunoreactivities were different in the submaxillary ganglion, in the nerves around blood vessels and acinus areas, but very similar in the areas of the excretory and striated duct of the SMG.